Mycoflora Isolated from Mazot and Solar Polluted Soils in Upper Egypt

Document Type : Original Article

Authors

Botany Department, Faculty of Science, Assiut University, Assiut, Egypt.

Abstract

FORTY-NINE species and two varieties belonging to 22 genera were recovered on dextrose and 1% crude oil Czapek's agar media from 48 soil samples polluted with mazot and solar. The hydrocarbons polluted soils were collected from three governorates in Upper Egypt; namely El-Minya, Assiut, and Sohag (8 samplesfrom each governorate for each hydrocarbon). The most common genus was Aspergillus which was isolated from the three governorates and from both hydrocarbon polluted soils, the most common species was Aspergillus fumigatus isolated from mazot polluted soils, while Aspergillus flavus, Aspergillus fumigatus, and Aspergillus terreus were the most common species isolated from solar polluted soils. Forty fungal isolates belonging to the 22 genera were tested for their ability to utilize crude oil in Czapek's medium at 28 ±1ºC. Out of these fungi, 32 isolates were able to grow forming visual growth and dry mass determined.


One of the key enzymes in oil utilization is lipase, therefore, the 40 isolates were subjected to lipase activity test. Remarkably, out of the tested fungi, 35 isolates produced visual growth and lipase activity, while 4 showed growth without producing the enzyme, these were Aspergillus awamorii, Chrysosporium tropicum, Trichoderma harzianum and Ulocladium chartarum. The highest recorded lipase productivity was observed by Fusarium verticilloides isolated from solar polluted soil at El-Minya giving 12.28 U/ml.